Golf clubhead and golf club assembly set

ABSTRACT

A golf clubhead formed therein with a hosel bore that has a tapered shape so that its diameter gradually increases toward the bottom. A shaft attachment member of a substantially cylindrical shape of which external shape being substantially the same as the shape of the hosel bore is installed in the hosel bore, and the shaft insertion hole formed in shaft attachment member so that a clubshaft is inserted therein is set to be inclined by a specified angle with respect to the sole of the clubhead.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a golf clubhead and golf club assembly set.

2. Description of the Related Art

Golf clubs in which the attachment angle (the so-called lie angle, loft angle or face angle) of a clubshaft with respect to the clubhead is made variable have been widely known.

For example, in the clubhead 2 of a conventional golf club 1 that is shown in FIG. 10 and disclosed in Japanese Patent Application Laid-Open (Kokai) No. H11-226155, a bore 3 is formed so that it extends from the upper part 2A toward the bottom part 2B of the clubhead 2, a hosel 5 that connects the clubhead 2 and a clubshaft 4 is inserted and fastened inside this bore 3. In this clubhead, a longitudinal hole 5A that is inclined at a specified angle with respect to the central axis L1 of the bore 3 is formed in the hosel 5, and the clubshaft 4 is inserted and fastened in the longitudinal hole 5A.

In this golf club 1, a plurality of different types of hosels 5 in which the inclination angles of the longitudinal holes 5A are different are prepared, so that the attachment angle of the clubshaft 4 with respect to the clubhead 2 is adjustable for each user.

However, in this conventional golf club 1, since the tip end of the hosel 5 is pointed, the force generated at the time of swing acts in the direction that causes the clubhead 2 to slip out of the hosel 5. Accordingly, the problem is that the clubhead has a tendency to slip out.

Furthermore, since the hosel 5 has a shape that causes the hosel to protrude on the upper part 2A of the clubhead 2, though the hosel 5 and clubshaft 4 can be firmly fastened, the center of gravity of the clubhead 2 is high, and it is difficult to improve the performance of the golf club 1.

BRIEF SUMMARY OF THE INVENTION

The present invention is to solve the problems seen in the conventional golf clubheads.

The object of the present invention is to provide a high-performance golf clubhead and golf club assembly set in which the slipping out of the clubhead from the clubshaft is assuredly prevented and in which the attachment and angle of the clubshaft can be easily adjusted.

The above object is accomplished by a unique structure of the present invention for a golf clubhead wherein the clubhead is comprised of:

-   -   a hosel bore which is formed in the clubhead and extends from         the upper part to the bottom part of the clubhead, the hosel         bore having a tapered shape such that its diameter gradually         increases toward the bottom part, and     -   a shaft attachment member of a substantially cylindrical shape         of which external shape being substantially the same as the         shape of the hosel bore, the shaft attachment member being         provided in the hosel bore and having a shaft insertion hole         which is inclined by a specified angle with respect to the sole         of the clubhead and in which a clubshaft is inserted.

In this structure, the shaft attachment member can be composed of a plurality of split pieces that are split in a circumferential direction of the shaft attachment member, and the shaft insertion hole of the shaft attachment member can be closed at the bottom.

In addition, a bonding agent for securing the shaft attachment member can be inserted between the outer circumferential surface of the shaft attachment member and the inner circumferential surface of the hosel bore and between the clubshaft and the inner circumferential surface of the shaft insertion hole of the shaft attachment member.

The diameter of the opening of the hosel bore on the upper part of the clubhead can be the same as that of the tip end of the clubshaft which is inserted in the shaft insertion hole.

The above object is accomplished by another unique structure of the present invention for a golf clubhead wherein the clubhead is comprised of:

-   -   a hosel bore which is formed in the clubhead and extends from         the upper part to the bottom part of the clubhead, the hosel         bore having a tapered shape such that the diameter of the hosel         bore gradually increases toward the bottom part, and     -   a substantially plate-form shaft supporting member provided in         the hosel bore in the vicinity of the bottom part, the shaft         supporting member being formed with a shaft through-hole that         allows a clubshaft to pass therethrough and to be supported         thereby.

In this structure, a bonding agent that secures the shaft supporting member in the hosel bore can be provided in the hosel bore.

The above object is accomplished by a unique structure of the present invention for a golf club assembly set that is composed of:

-   -   a clubshaft,     -   a clubhead main body formed therein with a hosel bore that         extends from the upper part to the bottom part of the clubhead         main body, the hosel bore having a tapered shape such that the         diameter increases toward the bottom part, and     -   a substantially cylindrical shaft attachment member that has an         external shape substantially the same as the shape of the hosel         bore and is to be inserted and fastened in the hosel bore from         the bottom part, the shaft attachment member being formed with a         shaft insertion hole which is inclined at a specified angle with         respect to the sole of the clubhead main body and into which the         clubshaft is inserted from the upper part side; and     -   the set includes a plurality of the shaft attachment members         with their shaft insertion holes being different in angles.

The above object is accomplished by another unique structure of the present invention for a golf club assembly set that is composed of:

-   -   a clubshaft,     -   a clubhead main body formed therein with a hosel bore that         extends from the upper part to the bottom part of the clubhead         main body, the hosel bore having a tapered shape such that its         diameter increases toward the bottom part, and     -   a substantially plate-form shaft supporting member to be         inserted and fastened in the hosel bore in the vicinity of the         bottom part, the shaft supporting member being provided with a         shaft through-hole that allows the clubshaft to pass         therethrough and to be supported thereby; and     -   the set includes a plurality of the shaft supporting members         with the shaft through-holes being different in positions and/or         angles.

According to the golf clubhead and golf club assembly set of the present invention, the slipping out of the clubhead from the clubshaft is assuredly prevented, and the adjustment of the attachment and angle of the clubshaft can be easily done.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows in cross section the golf clubhead according to the first embodiment of the present invention with a clubshaft attached thereto;

FIG. 2 is a top view of the clubhead of FIG. 1;

FIG. 3 is a bottom view of the clubhead of FIG. 1;

FIG. 4 is a schematic perspective view of the shaft attachment member used in the clubhead of FIG. 1;

FIG. 5 shows the golf club assembly set that uses the clubhead of the first embodiment of the present invention;

FIG. 6 shows in cross section the golf clubhead according to the second embodiment of the present invention;

FIG. 7 shows in cross section the golf clubhead according to the third embodiment of the present invention;

FIG. 8 shows the shaft supporting member used in the clubhead of FIG. 7;

FIG. 9 shows the golf club assembly set that uses the clubhead of the third embodiment of the present invention; and

FIG. 10 shows in cross section a conventional golf clubhead.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1 through 3, the golf clubhead 10 of the present invention is formed with a hosel bore 12 that formed in the clubhead and extends from the upper part 10A to the bottom part 10B.

The hosel bore 12 has a tapered shape, and the diameter of the hosel bore increases from the upper part 10A toward the bottom part 10B. The diameter of the opening 12A of the hosel bore 12 on the upper part 10A side is set to be substantially the same as the tip of the clubshaft 16 that is inserted in the hosel bore 12.

Furthermore, a substantially cylindrical shaft attachment member 14 which has an external shape that is substantially the same as the shape of the hosel bore 12 is inserted in the hosel bore 12 from the bottom part 10B side and fastened in this hosel bore 12.

As seen from FIG. 4, the shaft attachment member 14 in the shown embodiment is constructed from two split pieces, i.e., a first attachment unit 14A and a second attachment unit 14B. A shaft insertion hole 14C is, as shown in FIG. 1, formed in the shaft attachment member 14. The central axis L1 of the shaft insertion hole 14C is inclined by a specified angle α with respect to the sole (or sole surface) 10C of the clubhead 10. The shaft insertion hole 14C allows the insertion of the clubshaft 16 from the upper surface 10A side.

In the above structure, after the outer circumferential surface of the shaft attachment member 14 and the inner circumferential surface of the shaft insertion hole 14C are coated with a bonding agent, the clubshaft 16 is inserted into and fastened in the hosel bore 12 from the upper part 10A side of the clubhead, and the shaft attachment member 14 is inserted into and fastened in the hosel bore 12 from the bottom part 10B side of the clubhead. As a result, the golf clubhead 10, shaft attachment member 14 and clubshaft 16 are fastened together by means of a bonding agent layer 15 that is formed by the bonding agent hardened.

As seen from the above, the golf clubhead 10 of the above embodiment of the present invention is comprised of: a hosel bore 12 that is formed in the clubhead 10 and extends from the upper part 10A to the bottom part 10B of the clubhead and that has a tapered shape such that the diameter of the hosel bore gradually increases from the upper part 10A toward the bottom part 10B; and a substantially cylindrical shaft attachment member 14 that has an external shape substantially the same as the shape of the hosel bore 12 and is inserted and fastened in the hosel bore 12 from the bottom part 10B side, and this shaft attachment member 14 has a shaft insertion hole 14C which is inclined at a specified angle of a with respect to the sole surface 10C of the clubhead 10 and allows the clubshaft 16 to be inserted thereinto from the upper part 10A side. Accordingly, the slipping out of the clubhead 10 from the clubshaft 16 is assuredly prevented, and the attachment and angle of the clubshaft 16 can be easily adjusted.

As seen from FIG. 5, a golf club assembly set can be made with a clubshaft 20, a golf clubhead main body 22 which is the same as the clubhead 10 described above, and shaft attachment members 24, 26 and 28 which are the same as the shaft attachment member 14 described above and in which their shaft insertion holes 24A, 26A and 28A have different angles α1, α2 and α3. With this arrangement of these components, a golf club that meets the needs of each player is provided at a low cost, and the angle of the clubshaft 20 can be easily altered. The types of shaft attachment members used in the golf club assembly set are not limited to those shown above; and, for example, two types of shaft attachment members can be provided for the assembly set, and in addition four or more types of shaft attachment members can be prepared for the set.

In the above embodiment, since the shaft attachment member 14 is comprised of two split pieces, i.e., the first attachment unit 14A and second attachment unit 14B, the shaft attachment member 14 can be easily inserted and fastened in the hosel bore 12, and the adjustment of the attachment and angle of the clubshaft 16 is greatly facilitated.

Furthermore, since the diameter of the opening 12A of the hosel bore 12 on the upper part 10A of the clubhead is set to be substantially the same as the diameter of the tip end of the clubshaft 16 that is inserted in the hosel bore 12, the angle of the clubshaft 16 can be adjusted using the edge of the opening 12A as a supporting point. In this regard as well, the adjustment of the attachment and angle of the clubshaft 16 is facilitated.

Since the golf clubhead 10 of the present invention does not use a hosel, the weight of the clubhead 10 can be reduced; and since the clubhead is a so-called through-bore type golf clubhead, the center of gravity is low, the ball is easily lifted, and the club performance is high.

FIG. 6 shows the golf clubhead 30 of the second embodiment of the present invention.

The clubhead 30 of the second embodiment 6 includes a shaft attachment member 32, and the shaft insertion hole 32A formed in this shaft attachment member 32 is closed at the bottom, thus being different from the shaft attachment member 14 of the golf clubhead 10 that has a through bore.

With the clubhead 30 of the second embodiment, the clubshaft 16 is more firmly attached to the clubhead 30 than in the case of the clubhead 10.

Needless to say, a golf club assembly set substantially the same as the above golf club assembly set described with reference to the clubhead 10 can be obtained with the use of the clubhead 30 described in FIG. 6 that includes the shaft attachment member 32 in which the shaft insertion hole 32A is closed at the bottom.

FIGS. 7 and 8 show the clubhead 40 of the third embodiment of the present invention.

The clubhead 40 of the third embodiment includes, instead of the shaft attachment member 14 used in the above-described first embodiment, a substantially plate-form shaft supporting member 42. The shaft supporting member 42 is inserted and fastened in the hosel bore 12 in the vicinity of the bottom part 40B of the clubhead 40. The shaft supporting member 42 is formed with a shaft through-hole 42A that allows the passage and support of the clubshaft 16 therein.

Upon attaching a clubshaft 16 to the clubhead 40, the shaft supporting member 42 is inserted into the hosel bore 12 and is fastened to a cut-out 12B that is formed in the hosel bore 12. The clubshaft 16 is then passed through the shaft through-hole 42A of the shaft supporting member 42; and after the gap in the hosel bore 12 is filled with a bonding agent, the bonding agent is allowed to be hardened, so that the clubhead 40, shaft supporting member 42 and clubshaft 16 are fastened by a the hardened bonding agent that is in the form of a bonding agent layer 44.

In the golf clubhead 40 of this third embodiment, the adjustment of the attachment and angle of the clubshaft 16 is facilitated, and an effect similar to that of the above-described golf clubhead 10 is obtained.

Furthermore, as seen from FIG. 9, a golf club assembly set can be made with a clubshaft 50, a golf clubhead main body 52 which is the same as the clubhead 40 described above and shaft supporting members 54, 56 and 58 which are the same as the shaft supporting member 42 described above and in which their position and/or angle of the shaft through-hole 54A, 56A or 58A have different configurations. With this arrangement of these components, a golf club that meets the needs of each player can be provided at a low cost. The types of shaft supporting members used in the golf club assembly set are not limited to those shown above; and, for example, two types of shaft supporting members can be provided for the assembly set, and in addition four or more types of shaft supporting members can be prepared for each set.

The above-described golf clubhead and golf club assembly set of the present invention are not limited to the shapes and structures, etc., shown in the above-described embodiments; and various modifications can be made. 

1. A golf clubhead comprising: a hosel bore which is formed in said clubhead and extends from an upper part to a bottom part of said clubhead, said hosel bore having a tapered shape such that a diameter thereof gradually increases toward said bottom part, and a shaft attachment member of a substantially cylindrical shape of which external shape being substantially the same as said shape of said hosel bore, said shaft attachment member being provided in said hosel bore and having therein a shaft insertion hole which is inclined by a specified angle with respect to a sole of said clubhead and in which a clubshaft is inserted.
 2. The clubhead according to claim 1, wherein said shaft attachment member is comprised of a plurality of split pieces that are split in a circumferential direction of said shaft attachment member.
 3. The clubhead according to claim 1, wherein said shaft insertion hole of said shaft attachment member has a closed bottom.
 4. The clubhead according to claim 1, wherein a bonding agent is provided between an outer circumferential surface of said shaft attachment member and an inner circumferential surface of said hosel bore and between said clubshaft and an inner circumferential surface of said shaft insertion hole of said shaft attachment member.
 5. A golf clubhead comprising: a hosel bore which is formed in said clubhead and extends from an upper part to a bottom part of said clubhead, said hosel bore having a tapered shape such that a diameter of said hosel bore gradually increases toward said bottom part, and a substantially plate-form shaft supporting member provided in said hosel bore in the vicinity of said bottom part, said shaft supporting member being formed with a shaft through-hole that allows a clubshaft to pass therethrough and to be supported thereby.
 6. The clubhead according to claim 5, wherein a bonding agent is provided in said hosel bore so as to secure said shaft supporting member in said hosel bore.
 7. The clubhead according to any one of claims 1 through 6, wherein a diameter of an opening of said hosel bore on said upper part of said clubhead is substantially the same as that of an end portion of said clubshaft inserted in said hosel bore.
 8. A golf club assembly set comprising: a clubshaft, a clubhead main body formed therein with a hosel bore that extends from an upper part to a bottom part of said clubhead main body, said hosel bore having a tapered shape such that a diameter thereof increases toward said bottom part, and a substantially cylindrical shaft attachment member that has an external shape substantially the same as said shape of said hosel bore and is to be inserted into said hosel bore from said bottom part side, said shaft attachment member being formed with a shaft insertion hole which is inclined at a specified angle with respect to a sole of said clubhead main body and into which said clubshaft is inserted from said upper part side; and wherein said set includes a plurality of said shaft attachment members with said shaft insertion holes being different in angles.
 9. The golf club assembly set according to claim 8, wherein said shaft attachment member is comprised of a plurality of split pieces that are split in a circumferential direction of said shaft attachment member.
 10. The golf club assembly set according to claim 8, wherein said shaft insertion hole of said shaft attachment member has a closed bottom.
 11. A golf club assembly set comprising: a clubshaft, a clubhead main body formed therein with a hosel bore that extends from an upper part to a bottom part of said clubhead main body, said hosel bore having a tapered shape such that a diameter thereof increases toward said bottom part, and a substantially plate-form shaft supporting member to be inserted and fastened in said hosel bore in the vicinity of said bottom part, said shaft supporting member being provided with a shaft through-hole that allows said clubshaft to pass therethrough and to be supported thereby; and wherein said set includes a plurality of shaft supporting members with said shaft through-hole being different in positions and/or angles.
 12. The golf club assembly set according to any one of claims 8 through 11, wherein a diameter of an opening on an upper part of said hosel bore is substantially the same as that of said clubshaft which is inserted into said hosel bore. 